Response of bone sodium to acute changes in extracellular fluid composition (cat)

A study has been made of the effects of short term infusions of various acids, alkalies, NaCl and glucose solutions on bone sodium content in the cat. Bone water was unaffected by any of the procedures used. A decline in bone sodium, expressed as Na/Ca ratio, of 3.5–8.0% was observed in the various treatment groups. This is 15–100% of the exchangeable fraction. The magnitude of the decline in Na content was found to be independent of changes in blood pH, plasma Na concentration, and total ECF Na content, and the amount of acid or water infused. Sodium loading did not cause a rise in bone Na content. The nature of the stimulus or stimuli responsible for the observed change in bone Na is not apparent from these experiments.